Color banding

Hello,

I have recently been experiencing color banding on my MacBook Pro (2012). However, I do not have this issue when running Windows 7 BootCamp.

I have tried calibrating display, tried running Disk Utility (everything's fine), I checked to see if I messed with the settings in Accessability, but all are set where they should be for a normal view. Is the MacBook Pro supposed to display images/gradients like this? ( see http://en.wikipedia.org/wiki/Colour_banding )

I believe it might be due to software rather than hardware because I know it does not do this under Windows 7 BootCamp and I don't remember it doing it back when I had Lion OS X. 😟

Thanks!